Android SQLite - 没有这样的表错误(代码1)

时间:2015-07-29 21:05:23

标签: android database sqlite

我正在为公交时刻表开发Android应用程序。我有一个带停止和时间的SQLite数据库,但我目前正在尝试访问它的噩梦。我搜索了这个问题,但我无法找到解决方案。

我已经构建了一个DataBaseHelper类,使用以下代码扩展SQLiteOpenHelper

public class DataBaseHelper extends SQLiteOpenHelper {
    private static String DB_PATH;

    private static String DB_NAME = "BagesExpress_def";

    private SQLiteDatabase myDataBase;

    private final Context myContext;

    public DataBaseHelper(Context context){
        super(context, DB_NAME, null,1);
        this.myContext = context;
        this.DB_PATH = this.myContext.getDatabasePath(DB_NAME).getAbsolutePath();
    }

    public void createDatabase() throws IOException{
        boolean dbExist = checkDataBase();

        if(dbExist){
            Log.v("EXISTS", "dbExists");
        }else{
            this.getReadableDatabase();

            try{
                copyDataBase();
            } catch (IOException e){
                throw new Error ("Error copying data");
            }
        }
    }

    private boolean checkDataBase(){
        SQLiteDatabase checkDB = null;

        try{
            String myPath = DB_PATH;
            checkDB = SQLiteDatabase.openDatabase(myPath,null,SQLiteDatabase.OPEN_READONLY);
        }catch(SQLiteException e){

        }

        if(checkDB!=null){
            checkDB.close();
        }

        return checkDB != null;
    }

    private void copyDataBase() throws IOException{
        InputStream myInput = myContext.getAssets().open(DB_NAME);

        String outFilename = DB_PATH;

        OutputStream myOutput = new FileOutputStream(outFilename);

        byte[] buffer = new byte [1024];
        int length;

        while ((length = myInput.read(buffer))>0){
            myOutput.write(buffer,0,length);
        }

        myOutput.flush();
        myOutput.close();
        myInput.close();

    }

    public void openDataBase() throws SQLException{
        String myPath = DB_PATH;
        myDataBase = SQLiteDatabase.openDatabase(myPath,null, SQLiteDatabase.OPEN_READONLY);

    }

    public synchronized void close() {
        if(myDataBase!=null)
            myDataBase.close();

        super.close();
    }

    @Override
    public void onCreate (SQLiteDatabase db){

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
        if(newVersion>oldVersion)
            try{
                copyDataBase();
            }
            catch(IOException ioe){

            }
    }

    public List<Viatge> getViatges(int horaSortida, int paradaSortida, int paradaArribada){

        Log.v("DBPATH",DB_PATH);
        List<Viatge> viatges = new ArrayList<Viatge>();

        String selectQuery = "SELECT t1.run, t1.parada, t2.parada,t1.hora,t2.hora FROM directesDirBarna t1, directesDirBarna t2 \n" +
                "WHERE (t1.run = t2.run AND t1.parada = "+ paradaSortida +" AND t2.parada = " + paradaArribada +") \n" +
                "AND t1.Hora > "+ horaSortida +" AND t2.Hora <> '';";

        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = db.rawQuery(selectQuery, null);

        if (cursor.moveToFirst()){
            do{
                Viatge viatge = new Viatge();
                viatge.setParadaSortida(Integer.parseInt(cursor.getString(1)));
                viatge.setParadaArribada(Integer.parseInt(cursor.getString(2)));
                viatge.setHoraSortida(Integer.parseInt(cursor.getString(3)));
                viatge.setHoraArribada(Integer.parseInt(cursor.getString(4)));

                viatges.add(viatge);
            } while(cursor.moveToNext());

        }
        return viatges;
    }
}

testSQL活动中,我使用以下代码:

 public class SqlTest extends Activity {
    private DataBaseHelper myDBHelper;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sql_test);

        Button sqlButton = (Button)findViewById(R.id.SQLBtn);
        sqlButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                myDBHelper = new DataBaseHelper(getApplicationContext());

                try {
                    myDBHelper.openDataBase();
                }
                catch(SQLException sqle){
                }

                myDBHelper.getViatges(1000,1,10);
            }
        });

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_sql_test, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

当我按下按钮来获取数据库时,我收到以下错误:

  

android.database.sqlite.SQLiteException:没有这样的表:   directesDirBarna(代码1)

尽管我的数据库中存在此表。

我怀疑发生这种情况是因为我的代码无法找到数据库,因此它会创建一个空白的数据库,因此它无法在其中找到任何内容,但我无法找到发生这种情况的地方。

任何人都可以照亮我的路吗?非常感谢。

编辑:这已经解决了。我使用了这个https://github.com/jgilfelt/android-sqlite-asset-helper,从我的设备中卸载的应用程序,做了一个干净的构建,现在它工作。

1 个答案:

答案 0 :(得分:1)

我认为这个问题与查询sql本身有关:

String selectQuery =&#34; SELECT t1.run,t1.parada,t2.parada,t1.hora,t2.hora FROM directesDirBarna t1, directesDirBarna t2 \ n&#34; +                 &#34; WHERE(t1.run = t2.run AND t1.parada =&#34; + paradaSortida +&#34; AND t2.parada =&#34; + paradaArribada +&#34;)\ n&#34 ; +                 &#34; AND t1.Hora&gt; &#34; + horaSortida +&#34;和t2.Hora&lt;&gt; &#39;&#39 ;;&#34 ;;

你两次使用同一张桌子......